The present invention incorporates using vinylidene chloride monomers in combination with ethylenically unsaturated comonomers to prepare an emulsion polymerized interpolymer that is color stable, thermally and chemically stable, and provides barrier properties.
Vinylidene chloride copolymers are well known in the art to exhibit oxygen barrier properties. However, such vinylidene chloride copolymers are also thermally sensitive, exhibiting degradation and discoloration upon processing at elevated temperatures. The higher temperatures cause a breakdown of the copolymer which then causes discoloring in the article into which the copolymer is fabricated. The polymers of ethylenically unsaturated monomers exhibit a greater degree of clarity and a greater degree of heat stability than do vinylidene chloride copolymers but do not have the barrier properties of vinylidene chloride copolymers. Therefore, a polymer useful for applications requiring the properties of each copolymer that is, both clarity and low oxygen permeability, would be desirable.